The present invention relates generally to a table-mounted surgical retractor apparatus, and more particularly to an improved clamp assembly suitable for adjusting the spread between support rods to which surgical retractors are attached.
Surgical retractor apparatus such as disclosed in U.S. Pat. No. 4,617,916 to Bruce A. LeVahn et al include retractor blades clamped to opposite arms of a rigid unitary wishbone-shaped frame for holding back tissue and exposing the internal region at a surgical incision. A clamp secured between the frame and a rigid extension of the operating table allows the frame to be positioned with the arms on either side of the incision. Applicant's copending patent application Ser. No. 07/246,350 discloses an improvement in which the arms are separated to form a "split" wishbone-shaped frame of two support rods joined together by a single clamp adjustable about the table extension. The support rods, being relatively short compared to the unitary frame, permit them to be disassembled and conveniently autoclaved in a standard-size sterilizing tray.
In these and similar structures, the opposed arms or rods are fixed in a relatively widespread position ample for use with retractors on large patients and surgical procedures involving large incisions. However on children and small incisions, the arms of a full-size retractor support are too far apart. Retractor blades with long holders are required to reach the incision, thus reducing the overall rigidity of the retractor system. In addition, the widespread arms with outwardly projecting retractor holders limit the surgeon's physical proximity to a small incision. Conversely, smaller retractor supports suitable for use with children and with small incisions are unsuitable for large patients and larger incisions because the rods and retractor holders get in the way of the surgeon and operating assistants, restricting access to the surgical site. Thus, it is desirable to provide retractor supports in at least two different sizes: one for adults and large incisions, and one for children and small incisions.
Consequently, more versatile retractor apparatus have evolved in which the spread between the support rods is adjustable for various surgical procedures and for different size incisions or patients. These apparatus include clamping devices for fixing a desired amount of spread, but they are very difficult to adjust, and require the assistance of other persons.